Ice and snow weighing down tree limbs and power lines is the greatest cause of outages during winter storms.

PSEG Long Island wrapped up damage control for Thursday's nor'easter on Friday afternoon after a series of outages over the past 36 hours.

As of 1:30 p.m., the utility reported that all of the 13,721 customers across Long Island and the Rockaways to lose power had their electricity restored. Line crews, tree trimmers, and support personnel will remain on hand to deal with any outages that could come with this weekend's forecasted snows.

In preparation for this Thursday's storm, the utility performed system checks on critical transmission and distribution equipment; arranged for contractors, including tree crews, to assist the utility’s own skilled workforce; and performed logistics checks, ensuring availability of critical materials, fuel and other supplies. In addition, the utility coordinated with county and municipal emergency management personnel, informing them of the preparation work, what to expect and how workers will respond.

According to PSEG LI, the steady accumulation of snow and ice poses the most serious threat of creating power outages. Wet snow on wires and tree limbs, icing and strong winds all increase the possibility of downed wires, as do cars skidding on snow, ice or slush and striking utility poles.

The utility prepared for the storm over the past few days, performing system checks on critical equipment, arranging for contractors to assist its own workforce, ensuring the availability of critical repair materials and fuel, and coordinating with county and municipal emergency personnel.

In cases of lost power, PSEG LI asks residents to first check to see if their house is the only one in the neighborhood that is affected. If it is, check the fuse box for tripped circuit breakers or blown fuses. If the fuse box looks normal, check the wire between the house and the closest utility pole. Any downed wires should be reported as soon as possible.

Residents are advised to keep an emergency kit on hand, including a battery-powered radio, a corded telephone, flashlights and extra batteries, a first aid kit, bottled water, nonperishable food, a manual can opener, matches, candles, blankets and sleeping bags.

Residents are also advised to stay away from all downed power lines, whether on foot or in a car, and keep children away from areas with downed poles or wires. If a wire falls on a car, passengers should stay put until help arrives.